The maturity of electronic commerce and acceptance of the Internet as a daily tool by a continually growing user base of millions of users intensify the need for communication engineers to develop techniques for enhancing network performance. With the advances in processing power of desktop computers, the average user has grown accustomed to sophisticated multimedia applications, which place tremendous strain on network resources (e.g., switch capacity). Also, processor performance has advanced to the degree that, for applications running across networks, network delays compose the largest portion of application response times. At the same time, users have grown less tolerant of network delays, demanding comparable improvements from the network infrastructure. Therefore, network performance enhancing mechanisms are needed to optimize efficiency and reduce user response times. These mechanisms are imperative in systems with relatively high network latency, such as a satellite network.
FIG. 8 is a diagram of a conventional communication system for providing retrieval of web content by a personal computer (PC). PC 801 is loaded with a web browser 803 to access the web pages that are resident on web server 805; collectively the web pages and web server 805 denote a “web site.” PC 803 connects to a wide area network (WAN) 807, which is linked to the Internet 809. The above arrangement is typical of a business environment, whereby the PC 801 is networked to the Internet 809. A residential user, in contrast, normally has a dial-up connection (not shown) to the Internet 809 for access to the Web. The phenomenal growth of the Web is attributable to the ease and standardized manner of “creating” a web page, which can possess textual, audio, and video content.
Web pages are formatted according to the Hypertext Markup Language (HTML) standard which provides for the display of high-quality text (including control over the location, size, color and font for the text), the display of graphics within the page and the “linking” from one page to another, possibly stored on a different web server. Each HTML document, graphic image, video clip or other individual piece of content is identified, that is, addressed, by an Internet address, referred to as a Uniform Resource Locator (URL). As used herein, a “URL” may refer to an address of an individual piece of web content (HTML document, image, sound-clip, video-clip, etc.) or the individual piece of content addressed by the URL. When a distinction is required, the term “URL address” refers to the URL itself while the terms “web content”, “URL content” or “URL object” refers to the content addressed by the URL.
In a typical transaction, the user enters or specifies a URL to the web browser 803, which in turn requests a URL from the web server 805 using the HyperText Transfer Protocol (HTTP). The web server 805 returns an HTML page, which contains references to numerous embedded objects (i.e., web content), to the web browser 803. Upon receiving the HTML page, the web browser 803 parses the page to retrieve each embedded object. The retrieval process typically requires the establishment of separate communication sessions (e.g., TCP (Transmission Control Protocol) connections) to the web server 805. That is, after an embedded object is received, the TCP connection is torn down and another TCP connection is established for the next object. Given the richness of the content of web pages, it is not uncommon for a web page to possess over 30 embedded objects. This arrangement disadvantageously consumes network resources, but more significantly, introduces delay to the user.
Delay is further increased if the WAN 807 is a satellite network, as the network latency of the satellite network is conventionally a longer latency than terrestrial networks. In addition, because HTTP commonly utilizes a separate TCP connection for each transaction, the large number of transactions amplifies the response time perceived by the end-user.
Based on the foregoing, there is a clear need for improved approaches for retrieval of web content within a communication system. There is also a need to utilize standard protocols to minimize development costs, interoperate with existing web browsers and servers, and provide rapid industry acceptance. There is a further need for a web content retrieval mechanism that makes networks with relatively large latency viable and/or competitive for Internet access. Therefore, an approach for retrieving web content that reduces response times perceived by users is highly desirable.